Method for fabricating touch panel

ABSTRACT

A method for fabricating a touch panel is provided. A first substrate and a second substrate are provided. A first carbon nanotube composite layer is applied on a surface of the first substrate to obtain a first electrode plate. A second carbon nanotube composite layer is applied on a surface of the first substrate to obtain a second electrode plate. The first and second electrode plates are assembled to obtain the touch panel.

RELATED APPLICATIONS

This application is continuation of application entitled, “LIQUIDCRYSTAL DISPLAY SCREEN”, U.S. application Ser. No. 12/459,566, filedJul. 2, 2009. This application is related to applications entitled,“LIQUID CRYSTAL DISPLAY SCREEN”, U.S. application Ser. No. 12/583,161,filed Aug. 13, 2009; “LIQUID CRYSTAL DISPLAY SCREEN”, U.S. applicationSer. No. 12/583,154, filed Aug. 13, 2009; “LIQUID CRYSTAL DISPLAYSCREEN”, U.S. application Ser. No. 12/459,545, filed Jul. 2, 2009;“TOUCH PANEL”,U.S. application Ser. No. 12/583,162 , filed Aug. 13,2009; “METHOD FOR MAKING TOUCH PANEL”, U.S. application Ser. No.12/584,415, filed Sep. 3, 2009; “TOUCH PANEL AND DISPLAY DEVICE ADOPTINGTHE SAME”, U.S. application Ser. No. 12/584,387, filed Sep.3, 2009;“METHOD FOR MAKING LIQUID CRYSTAL DISPLAY SCREEN”, U.S. application Ser.No. 12/583,160, filed Aug. 13, 2009; “METHOD FOR MAKING LIQUID CRYSTALDISPLAY SCREEN”, U.S. application Ser. No. 12/584,410, filed Sep. 3,2009; “TOUCH PANEL”, U.S. application Ser. No. 12/286,266, filed Sep.29, 2008; “TOUCH PANEL”, U.S. application Ser. No. 12/286,141, filedSep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, U.S.application Ser. No. 12/286,189, filed Sep. 29, 2008; “TOUCH PANEL ANDDISPLAY DEVICE USING THE SAME”, U.S. application Ser. No. 12/286,181,filed Sep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”,U.S. application Ser. No. 12/286,176, filed Sep. 29, 2008; “TOUCH PANELAND DISPLAY DEVICE USING THE SAME”, U.S. application Ser. No.12/286,166, filed Sep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICE USINGTHE SAME”, U.S. application Ser. No. 12/286,178, filed Sep. 29, 2008;“TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, U.S. application Ser.No. 12/286,148, filed Sep. 29, 2008; “TOUCHABLE CONTROL DEVICE”, U.S.application Ser. No. 12/286,140, filed Sep. 29, 2008; “TOUCH PANEL ANDDISPLAY DEVICE USING THE SAME”, U.S. application Ser. No. 12/286,154,filed Sep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”,U.S. application Ser. No. 12/286,216, filed Sep. 29, 2008; “TOUCH PANELAND DISPLAY DEVICE USING THE SAME”, U.S. application Ser. No.12/286,152, filed Sep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICE USINGTHE SAME”, U.S. application Ser. No. 12/286,146, filed Sep. 29, 2008;“TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, U.S. application Ser.No. 12/286,145, filed Sep. 29, 2008; “TOUCH PANEL, METHOD FOR MAKING THESAME, AND DISPLAY DEVICE ADOPTING THE SAME”, U.S. application Ser. No.12/286,155, filed Sep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICE USINGTHE SAME”, U.S. application Ser. No. 12/286,179, filed Sep. 29, 2008;“TOUCH PANEL, METHOD FOR MAKING THE SAME, AND DISPLAY DEVICE ADOPTINGTHE SAME”, U.S. application Ser. No. 12/286,228, filed Sep. 29, 2008;“TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, U.S. application Ser.No. 12/286,153, filed Sep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICEUSING THE SAME”, U.S. application Ser. No. 12/286,184, filed Sep. 29,2008; “METHOD FOR MAKING TOUCH PANEL”, U.S. application Ser. No.12/286,175, filed Sep. 29, 2008; “METHOD FOR MAKING TOUCH PANEL”, U.S.application Ser. No. 12/286,195, filed Sep. 29, 2008; “TOUCH PANEL ANDDISPLAY DEVICE USING THE SAME”, U.S. application Ser. No. 12/286,160,filed Sep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”,U.S. application Ser. No. 12/286,220, filed Sep. 29, 2008; “TOUCH PANELAND DISPLAY DEVICE USING THE SAME”, U.S. application Ser. No.12/286,227, filed Sep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICE USINGTHE SAME”, U.S. application Ser. No. 12/286,144, filed Sep. 29, 2008;“TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, U.S. application Ser.No. 12/286,218, filed Sep. 29, 2008; “TOUCH PANEL AND DISPLAY DEVICEUSING THE SAME”, U.S. application Ser. No. 12/286,148, filed Sep. 29,2008; “TOUCH PANEL AND DISPLAY DEVICE USING THE SAME”, U.S. applicationSer. No. 12/286,241, filed Sep. 29, 2008; “TOUCH PANEL, METHOD FORMAKING THE SAME, AND DISPLAY DEVICE ADOPTING THE SAME”, U.S. applicationSer. No. 12/286,151, filed Sep. 29, 2008; “ELECTRONIC ELEMENT HAVINGCARBON NANOTUBES”, U.S. application Ser. No. 12/286,143, filed Sep. 29,2008; and “TOUCH PANEL, METHOD FOR MAKING THE SAME, AND DISPLAY DEVICEADOPTING THE SAME”, U.S. application Ser. No. 12/286,219, filed Sep. 29,2008; and “PERSONAL DIGITAL ASSISTANT”, U.S. application Ser. No.12/384,329, filed Apr. 2, 2009.

BACKGROUND

1. Technical Field

The present disclosure relates to a method for fabricating a touchpanel.

2. Description of Related Art

Liquid crystal displays (LCDs) are typically used as the display invarious devices such as computers, and vehicle and airplaneinstrumentation. Following the advancement in recent years of variouselectronic apparatuses toward high performance and diversification,there has been continuous growth in the number of electronic apparatusesequipped with optically transparent touch panels at the front of theirrespective display devices (e.g., liquid crystal panels). Users mayoperate a touch panel by pressing or touching the touch panel with afinger, a pen, a stylus, or a like tool while visually observing theliquid crystal display through the touch panel. Therefore, a demandexists for touch panels that are superior in visibility and reliable inoperation.

At present, different types of touch panels, including resistance,capacitance, infrared, and surface sound-wave types have been developed.Resistance-type touch panels have been widely used due to their highaccuracy and low cost of production.

A conventional resistance-type touch panel includes an upper substrate,a transparent upper conductive layer formed on a lower surface of theupper substrate, a lower substrate, a transparent lower conductive layerformed on an upper surface of the lower substrate, and sometimes, aplurality of dot spacers formed between the transparent upper conductivelayer and the transparent lower conductive layer. The transparent upperconductive layer and the transparent lower conductive layer are formedof electrically conductive indium tin oxide (ITO).

In operation, an upper surface of the upper substrate is pressed with afinger, a pen, or a like tool, and visual observation of a screen on theliquid crystal display device provided on a back side of the touch panelis provided. This causes the upper substrate to be deformed, and theupper conductive layer thus comes in contact with the lower conductivelayer at the position where the pressing occurs. An electronic circuitseparately applies voltages to the transparent upper conductive layerand the transparent lower conductive layer. Thus, the electronic circuitcan detect the deformed position.

Each of the transparent conductive layers (e.g., ITO layers) isgenerally formed by means of ion-beam sputtering, and this method isrelatively complicated. Additionally, the ITO layer has poorwearability/durability, low chemical endurance, and uneven resistanceover an entire area of the touch panel. All the above-mentioned problemsof the ITO layer make for a touch panel and a liquid crystal displayscreen with low sensitivity and short lifetime.

What is needed, therefore, is to provide a method for making the touchpanel in which the above problems are eliminated or at least alleviated.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present touch panel, the liquid crystal displayscreen using the same, and the methods for making the touch panel andthe liquid crystal display screen can be better understood withreference to the following drawings. The components in the drawings arenot necessarily drawn to scale; the emphasis instead being placed uponclearly illustrating the principles of the present touch panel, theliquid crystal display screen using the same, and the methods for makingthe touch panel and the liquid crystal display screen.

FIG. 1 is a schematic view of a partially assembled touch panel inaccordance with an embodiment.

FIG. 2 is a cross-sectional view of the touch panel of FIG. 1.

FIG. 3 is a schematic view of a carbon nanotube layer used in the touchpanel of FIG. 1.

FIG. 4 shows an SEM image of a carbon nanotube film.

FIG. 5 is a structural schematic of a carbon nanotube segment.

FIG. 6 shows a Scanning Electron Microscope (SEM) image of a carbonnanotube composite layer.

FIG. 7 shows a linear relationship of the resistance of the carbonnanotube composite layer according to one embodiment.

FIG. 8 is a flow chart of a method for making a touch panel.

FIG. 9 shows a schematic view of a method for making the touch panel.

FIG. 10 shows an SEM image of a carbon nanotube film before irradiationby laser.

FIG. 11 shows an SEM image of a carbon nanotube film after irradiationby laser.

FIG. 12 shows a schematic view of a heat-pressed process used to form aheat-pressed carbon nanotube composite layer.

FIG. 13 shows a schematic view of a method for continuously making anelectrode plate.

FIG. 14 shows a schematic view of a liquid crystal display with a touchpanel.

FIG. 15 shows a schematic view of a thin film transistor panel of theliquid crystal display screen.

FIG. 16 is a cross sectional view of a thin film transistor.

FIG. 17 shows an SEM image of a carbon nanotube film with the carbonnanotubes therein arranged side by side.

FIG. 18 is essentially a schematic cross-sectional view of the liquidcrystal display screen with a touch panel, showing operation with atouch tool.

FIG. 19 is a flow chart of a method for making the liquid crystaldisplay screen.

FIG. 20 shows a schematic view of a method for making the uppercomponent.

FIG. 21 shows a schematic view of a method for making the bottom plate,in accordance with one embodiment.

FIG. 22 shows a schematic view of a method for making the thin filmtransistor panel.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate at least one exemplary embodiment of the present touch panel,the liquid crystal display screen using the same, and the methods formaking the touch panel and the liquid crystal display screenincorporating the same, in at least one form, and such exemplificationsare not to be construed as limiting the scope of the disclosure in anymanner.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made to the drawings to describe, in detail,embodiments of the present touch panel, the liquid crystal displayscreen using the same, and the methods for making the touch panel andthe liquid crystal display screen.

Touch Panel

Referring to FIG. 1 and FIG. 2, a touch panel 10 includes a firstelectrode plate 12, a second electrode plate 14, and a plurality of dotspacers 16 located between the first electrode plate 12 and the secondelectrode plate 14.

The first electrode plate 12 includes a first substrate 120, a firstconductive layer 122, and two first-electrodes 124. The twofirst-electrodes 124 and the first conductive layer 122 are located onthe second surface 1204 of the first substrate 120. The twofirst-electrodes 124 can be located on the first conductive layer 122,or the two first-electrodes 124 can be located on the first substrate120 and electrically connected to the first conductive layer 122. Adirection from one of the first-electrodes 124 across the firstconductive layer 122 to the other first electrode 124 is defined as afirst direction.

The second electrode plate 14 includes a second substrate 140, a secondconductive layer 142, and two second electrodes 144. The secondsubstrate 140 includes substantially flat first surface 1402 and secondsurface 1404. The two second electrodes 144 and the second conductivelayer 142 are located on the first surface 1402 of the second substrate140. The two second electrodes 144 can be located on second conductivelayer 142, or the two second electrodes 144 can be located on the secondsubstrate 140 and electrically connected to the second conductive layer142. A direction from one of the second electrodes 144 across the secondconductive layer 142 to the other second electrode 144 is defined as asecond direction and is perpendicular to the first direction.

The first substrate 120 and the second substrate 140 can be transparentplates, sheets or films. The first substrate 120 can be made of flexiblematerials, such as plastic and resin. The second substrate 140 can bemade of rigid materials, such as glass, quartz and diamond, or can bemade of flexible material. The second substrate 140 can be configuredfor supporting the second conductive layer 142. When the first substrate120 and the second substrate 140 are made of flexible materials and haveflexible planer structures, a thickness of the first substrate 120 orthe second substrate 140 can range from about 0.01 millimeters to about1 centimeter. Materials of the first substrate 120 and the secondsubstrate 140 can be selected from a group consisting of polycarbonate(PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET),PES, cellulose acetate, benzocyclobutene, polyvinyl chloride (PVC), anyother acrylic resins, and any combination thereof. In one embodiment,both the first substrate 120 and the second substrate 140 are PET filmsand the thickness of the first substrate 120 or the second substrate 140is about 2 millimeters. It can be understood that the materials of thefirst substrate 120 and the second substrate 140 are not limited, andcan be any materials that have suitable degree of transparency and makesthe first substrate 120 flexible and the second substrate 140 strongenough to support the second conductive layer 142.

The first-electrodes 124 and the second electrodes 144 comprise ofconductive materials, such as metals, conductive polymer materials, orcarbon nanotubes. The metals can be gold, silver, copper or any othermetal having a good conductivity. The conductive polymer materials canbe polyacetylene, polyparaphenylene, polyaniline, or polythiophene. Inone embodiment, the first-electrodes 124 and second electrodes 144 aremade of conductive silver pastes.

An insulating layer 18 is provided between the first and the secondelectrode plates 12 and 14. The first electrode plate 12 can be locatedon the insulating layer 18. The first conductive layer 122 is oppositeto, but is spaced from, the second conductive layer 142. The dot spacers16, if employed, are separately located between the conductive layers122, 142. A distance between the second electrode plate 14 and the firstelectrode plate 12 can range from about 2 micrometers to 20 micrometers.The insulating layer 18 and the dot spacers 16 can be made of insulativeresins or any other suitable insulative material. Therefore, insulationbetween the first electrode plate 12 and the second electrode plate 14is provided by the insulating layer 18 and the dot spacers 16. It is tobe understood that the dot spacers 16 are optional, particularly whenthe touch panel 10 is relatively small. Their need is governed by thesize of the span and the strength of the first electrode plate 12.

In some embodiments, at least one of the first conductive layer 122comprises a Touch Panel (TP) carbon nanotube layer or a first TP carbonnanotube composite layer. At least one of the second conductive layer142 comprises a Touch Panel (TP) carbon nanotube layer or a second TPcarbon nanotube composite layer. The TP carbon nanotube layer can becomposed of one or more carbon nanotube films. The thickness of the TPcarbon nanotube layer or a TP carbon nanotube composite layer can be ina range from about 0.5 nanometers to about 1 millimeter. The thicknessof the carbon nanotube film can be in a range from about 0.5 nanometersto about 100 micrometers.

It is to be understood that the size of the touch panel 10 is notconfined by the size of the carbon nanotube films. When the size of thecarbon nanotube films is smaller than the desired size of the touchpanel 10, a plurality of carbon nanotube films in each conductive layercan be coplanar, located side by side and/or overlapping to cover theentire surface of the first and second substrates 120, 140. Thus, thesize of the touch panel 10 can be set as desired. In each conductivelayer, a plurality of carbon nanotube films can be stacked with eachother, and thus, a thickness of the carbon nanotube layer can be set ina range where each conductive layer has an acceptable transparency.Alignment directions of the carbon nanotube films can be as desired.

TP Carbon Nanotube Layer

The TP carbon nanotube layer 149 has a planar structure and the carbonnanotubes therein are uniformly distributed. A thickness of the TPcarbon nanotube layer 149 can range from about 0.5 nanometers to 100micrometers. Referring to FIG. 3, the TP carbon nanotube layer 149 caninclude one or more carbon nanotube films 141 having a plurality ofcarbon nanotubes therein. The carbon nanotubes in the carbon nanotubefilm 141 are orderly or disorderly distributed to form an ordered carbonnanotube film 141 or a disordered carbon nanotube film 141. The term‘disordered carbon nanotube film’ includes, but not limited too, a filmwhere the carbon nanotubes are arranged along many different directions,arranged such that the number of carbon nanotubes arranged along eachdifferent direction can be almost the same (e.g. uniformly disordered);and/or entangled with each other. ‘Ordered carbon nanotube film’includes, but not limited to, a film where the carbon nanotubes arearranged in a consistently systematic manner, e.g., the carbon nanotubesare arranged approximately along a same direction and or have two ormore sections within each of which the carbon nanotubes are arrangedapproximately along a same direction (different sections can havedifferent directions).

In the disordered film, the carbon nanotubes are disordered. Thedisordered film can be isotropic. The disordered carbon nanotubes can beattracted to each other by van der Waals attractive therebetween. Theindividual carbon nanotubes can be substantially parallel to a surfaceof the carbon nanotube film 141. Two or more stacked carbon nanotubefilms 141 may be used in each conductive layer. Carbon nanotubes inadjacent ordered carbon nanotube films 141 can be arranged along a samedirection or different directions.

The ordered film can be a carbon nanotube film 141 directly drawn from acarbon nanotube array. Referring to FIGS. 4 and 5, the drawn carbonnanotube film 141 can include a plurality of successively orientedcarbon nanotube segments 143 joined end-to-end by van der Waalsattractive force therebetween. Each carbon nanotube segment 143 includesa plurality of carbon nanotubes 145 parallel to each other, and combinedby van der Waals attractive force therebetween. The carbon nanotubesegments 143 can vary in width, thickness, uniformity and shape. Thecarbon nanotubes 145 in the carbon nanotube film 141 are also orientedalong a preferred orientation. When the carbon nanotube layer 149includes two or more stacked drawn carbon nanotube films 141, the anglebetween the aligned directions of the carbon nanotubes in the adjacenttwo drawn carbon nanotube films 141 ranges from above or equal to 0degrees to about 90 degrees. The carbon nanotubes in the carbon nanotubefilm can be selected from a group consisting of single-walled,double-walled, and/or multi-walled carbon nanotubes. The diameter of thesingle-walled carbon nanotubes ranges from about 0.5 nm to about 50 nm,the diameter of the double-walled carbon nanotubes ranges from about 1.0nm to about 50 nm, and the diameter of the multi-walled carbon nanotubesranges from about 1.5 nm to about 50 nm.

In one embodiment, the first conductive layer 122 and the secondconductive layer 142 both include the drawn carbon nanotube films 141.The carbon nanotubes 145 in the first conductive layer 122 are arrangedalong the first direction, and the carbon nanotubes 145 in the secondconductive layer 142 are arranged along the second direction. The firstdirection is perpendicular to the second direction. Thus, theconductivities between the two first-electrodes 124 and between the twosecond electrodes 144 can be improved by the alignment of the carbonnanotubes 145. As shown in FIG. 4, the majority of the carbon nanotubes145 are arranged along a primary direction; however, the orientation ofsome of the carbon nanotubes 145 may vary.

TP Carbon Nanotube Composite Layer

The first and second TP carbon nanotube composite layers have samestructures and configurations. Only for simple, the first and second TPcarbon nanotube composite layers are detailedly described in followingas the TP carbon nanotube composite layer. Referring to FIG. 6, the TPcarbon nanotube composite layer comprises a carbon nanotube film 141 andpolymer materials infiltrating the carbon nanotube film 141. It is to beunderstood that spaces are existed in the adjacent carbon nanotubes inthe carbon nanotube film 141, and thus the carbon nanotube film 141includes a plurality of micropores defined by the adjacent carbonnanotubes therein. The polymer material is filled into the micropores inthe carbon nanotube film 141 to form the TP carbon nanotube compositelayer. The polymer materials can be distributed uniformly in the TPcarbon nanotube layer 149. The TP carbon nanotube composite layerincludes one or more carbon nanotube films 141. The TP carbon nanotubecomposite layer can have a uniform thickness. A thickness of the carbonnanotube composite layer is only limited by the degree of transparencydesired. In one embodiment, the thickness of the carbon nanotubecomposite layer can range from about 0.5 nanometers to about 1millimeter. The polymer material can be transparent, and not limited toa specific material. The polymer material can be selected from a groupconsisting of polystyrene, polyethylene, polycarbonate, polymethylmethacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate(PET), Benzo Cyclo Butene (BCB), and polyalkenamer. In one embodiment,the polymer material is PMMA. The polymer material can improve theconnection between the TP carbon nanotube composite layer and thesubstrate.

Furthermore, referring to FIG. 7, due to the polymer materialinfiltrated into the TP carbon nanotube composite layer, unwanted shortcircuits in the TP carbon nanotube composite layer can be eliminated,and thus the resistance of the TP carbon nanotube composite layer has anearly linear relationship with length. Accordingly, the accuracy of thetouch panel 10 can be improved.

It is to be understood that, the TP carbon nanotube composite layer alsocan comprise a plurality of separately preformed carbon nanotubecomposite films located side by side or stacked with each other.

In one embodiment, both the first conductive layer 122 and the secondconductive layer 142 include a carbon nanotube composite layer formed bya drawn carbon nanotube film 141 and PMMA distributed uniformly therein.Specifically, the PMMA is distributed in the spaces between adjacentcarbon nanotubes in the carbon nanotube film 141. The carbon nanotubesin the first conductive layer 122 are arranged along the firstdirection, and the carbon nanotubes in the second conductive layer 142are arranged along the second direction. It is to be understood thatsome variation can occur in the orientation of the carbon nanotubes inthe carbon nanotube film 141 as can be seen in FIGS. 4 and 6.

A transparent protective film 126 can be further located on the topsurface of the touch panel 10 (e.g., on the first surface 1202 of thefirst substrate 120). The transparent protective film 126 can be a filmthat receives a surface hardening treatment to protect the firstelectrode plate 12 from being scratched when the touch panel 10 is inuse. The transparent protective film 126 can be plastic or resin.

The touch panel 10 can further include a shielding layer 152 located onthe lower surface of the second substrate 140 (e.g., on the secondsurface 1404 of the second substrate 140). The material of the shieldinglayer 152 can be selected from a group consisting of indium tin oxide,antimony tin oxide, carbon nanotube film 141, and other conductivematerials. In one embodiment, the shielding layer 146 is a carbonnanotube film 141. The shielding layer 152 is connected to ground andplays a role of shielding and, thus, enables the touch panel 10 tooperate without interference (e.g., electromagnetic interference).Furthermore, a passivation layer 154 can be located on a surface of theshielding layer 152, on the side away from the second substrate 140. Thematerial of the passivation layer 154 can, for example, be siliconnitride or silicon dioxide. The passivation layer 154 can protect theshielding layer 152 from chemical or mechanical damage.

The touch panel 10 can be located on a display device. The displaydevice can be a monochrome display, color graphics adapter (CGA)display, enhanced graphics adapter (EGA) display,variable-graphics-array (VGA) display, super VGA display, liquid crystaldisplay (LCD), cathode ray tube (CRT), plasma displays and the like. Thedisplay device with the touch panel 10 thereon is operatively coupled toa processor and may be a separated component (peripheral device) or beintegrated with the processor and program storage to form a desktopcomputer (all in one machine), a laptop, handheld or tablet or the like.

Method for Making Touch Panel

Referring to FIGS. 8 and 9, a method for making the touch panel 10according to one embodiment includes the following steps of: (S10)supplying the first substrate 120; (S20) applying the first conductivelayer 122 on the first substrate 120 to acquire the first electrodeplate 12; (S30) repeating the above-described steps to acquire thesecond electrode plate 14; and (S40) assembling the first electrodeplate 12 and the second electrode plate 14 together to form the touchpanel 10.

In step (S10), the first substrate 120 can have a flexible planerstructure and be made of flexible material. A thickness of the firstsubstrate 120 can range from about 0.01 millimeters to about 1centimeter. Material of the first substrate 120 can be selected from agroup consisting of polycarbonate (PC), polymethyl methacrylate (PMMA),polyethylene terephthalate (PET), PES, cellulose acetate,benzocyclobutene, polyvinyl chloride (PVC), and any other acrylicresins, and any combination thereof. In one embodiment, the firstsubstrate 120 is a PET film, the thickness of the first substrate 120 isabout 2 millimeters, the width of the first substrate 120 is about 20centimeters, and the length of the first substrate 120 is about 30centimeters. It can be understood that the material of the substrates isonly limited by the desired degree of transparency and flexibilitysought for the substrates.

When the first conductive layer 122 includes the TP carbon nanotubelayer 149, step (S20) can include the following steps of: (S201)providing at least one carbon nanotube film 141; (S202) treating the atleast one carbon nanotube film 141 by a laser to improve thetransparency of the at least one carbon nanotube film 141; and (S203)laying the at least one carbon nanotube film 141 on the second surface1204 of the first substrate 120.

In step (S201), the carbon nanotube film 141 can be an ordered carbonnanotube film 141 or a disordered carbon nanotube film 141. The carbonnanotube film 141 can be formed in many ways including a directlygrowing method, a pressing method, a flocculating method, or a drawingmethod. The method for directly growing a carbon nanotube film 141 canbe executed by growing a plurality of carbon nanotubes on a substrate bya chemical vapor deposition method to form a carbon nanotube film 141,and the carbon nanotubes therein are disorderly arranged. The carbonnanotube film 141 is a disordered film.

Forming a carbon nanotube film 141 by the flocculating method can beexecuted by providing carbon nanotubes; flocculating the carbonnanotubes in a solvent to acquire a carbon nanotube floccule structure;separating the carbon nanotube floccule structure from the solvent; andshaping the separated carbon nanotube floccule structure into the carbonnanotube film 141 in which the carbon nanotubes are entangled with eachother and isotropic.

Forming a carbon nanotube film 141 by the pressing method can beexecuted by providing an array of carbon nanotubes formed on asubstrate; and providing a pressing device to press the array of carbonnanotubes, thereby forming a carbon nanotube film 141 in which thecarbon nanotubes are arranged along one direction, or two or moredirections.

In one embodiment, the carbon nanotube film 141 is a drawn carbonnanotube film 141 formed by the drawing method. The drawing method isexecuted by drawing the drawn carbon nanotube film 141 from a carbonnanotube array, and includes the following steps of: providing an arrayof carbon nanotubes; and pulling out a drawn carbon nanotube film 141from the array of carbon nanotubes. Pulling can be aided by the use of atool such as adhesive tape, pliers, tweezers, or other tools allowingmultiple carbon nanotubes to be gripped and pulled simultaneously.

The drawn carbon nanotube film 141 can be formed by the substeps of:selecting one or more carbon nanotubes having a predetermined width fromthe array of carbon nanotubes; and pulling the carbon nanotubes at auniform speed to form carbon nanotube segments that are joined end toend to achieve a uniform drawn carbon nanotube film 141.

The carbon nanotube segments can be selected by using a tool, such asadhesive tapes, pliers, tweezers, or other tools allowing multiplecarbon nanotubes to be gripped and pulled simultaneously to contact withthe array of carbon nanotubes. Referring to FIG. 4 and FIG. 5, eachcarbon nanotube segment 143 includes a plurality of carbon nanotubes 145parallel to each other, and combined by van der Waals attractive forcetherebetween. The pulling direction can be substantially perpendicularto the growing direction of the array of carbon nanotubes.

Because of the van der Waals attractive force, the carbon nanotubes inthe drawn carbon nanotube film 141 are easy to bundle together to formcarbon nanotube strings with a large diameter. The carbon nanotubestrings have relatively low light transmittance and thus affect thelight transmittance of the drawn carbon nanotube film 141. The laserwith a power density greater than 0.1×10⁴ W/m² can be used to irradiatethe drawn carbon nanotube film 141 to improve the light transmittance ofthe drawn carbon nanotube film 141 by removing the carbon nanotubestrings having a low light transmittance. Step (S202) can be executed inan oxygen comprising atmosphere. In one embodiment, step (S202) isexecuted in an ambient atmosphere. It is also understood that the lasertreatment can be used on any carbon nanotube film.

Step (S202) can be executed by many methods. In one method, the drawncarbon nanotube film 141 is fixed and a laser device moving at aneven/uniform speed is used to irradiate the fixed drawn carbon nanotubefilm 141. In another method, the laser device is fixed, and the drawncarbon nanotube film 141 is moved through the light of the laser.

The carbon nanotubes absorb energy from the laser irradiation and atemperature of the drawn carbon nanotube film 141 is increased. Thelaser irradiation can target the carbon nanotube strings with largerdiameters, because they will absorb more energy and be destroyed,leaving strings with smaller diameters and higher light transmittance,resulting in a drawn carbon nanotube film 141 having a relatively higherlight transmittance. Referring to FIG. 11, we can see that the drawncarbon nanotube film 141 irradiated by the laser has a relatively higherlight transmittance (can be more than 70% higher) than that in FIG. 10that has not been irradiated with the laser.

It can be understood that any or all of the carbon nanotube films can betreated with an organic solvent. Specifically, the drawn carbon nanotubefilm 141 can be treated by applying organic solvent. Alternatively, thedrawn carbon nanotube film 141 can be put into a container, which isfilled with the needed organic solvent. The organic solvent isvolatilizable and can be selected from, among others, a group consistingof ethanol, methanol, acetone, dichloroethane, chloroform, and anysuitable mixture thereof. In one embodiment, the organic solvent isethanol. The supporter can be a substrate. After being soaked by theorganic solvent, microscopically, carbon nanotube strings will be formedby adjacent carbon nanotubes, or portions thereof, bundling in thecarbon nanotube film 141, due to the surface tension of the organicsolvent as it volatizes. In one aspect, some and/or parts of the carbonnanotubes in the untreated drawn carbon nanotube film 141 that are notadhered on the substrate will adhere on the substrate after the organicsolvent treatment due to the surface tension of the organic solvent. Thecontact area of the drawn carbon nanotube film 141 with the substratewill increase, and thus, the drawn carbon nanotube film 141 will adhereto the surface of the first substrate 340 more firmly. In anotheraspect, due to the decrease of the specific surface area via bundling,the mechanical strength and toughness of the drawn carbon nanotube film141 are increased and the coefficient of friction of the drawn carbonnanotube film 141 is reduced. Macroscopically, a treated drawn carbonnanotube film 141 has approximately a uniform structure.

Optional step (S202) is used to improve the light transmittance of thedrawn carbon nanotube film 141.

In step (S203), as described above, the drawn carbon nanotube film 141can be simply laid on the second surface 1204 of the first substrate120. The drawn carbon nanotube film 141 is adhesive in nature. As such,the drawn carbon nanotube film 141 can be directly adhered to the secondsurface 1204 of the first substrate 120. Further, a plurality of drawncarbon nanotube films 141 can be stacked or located side by side on thesecond surface 1204 of the first substrate 120 to form the abovedescribed carbon nanotube layer.

In one embodiment, when the first conductive layer 122 includes thecarbon nanotube composite layer, step (S20) can include the followingsteps of: (S211) coating a layer of polymer solution on the surface ofthe first substrate 120; (S212) optionally treating a carbon nanotubefilm 141 with laser light; (S213) placing the carbon nanotube film 141on the layer of polymer solution; and (S214) infiltrating the polymersolution into the carbon nanotube film 141, and curing the polymersolution to form the TP carbon nanotube composite layer.

In step (S211), a tool such as a brush can be used to apply a coat ofthe polymer solution on the surface of the first substrate 120, or thesurface of the first substrate 120 can be immersed in the polymersolution. It can be understood that the method for forming the layer ofpolymer solution is not limited to the above-described method. It isalso understood that the polymer can be added to any carbon nanotubefilm.

The polymer solution can be formed by dissolving a polymer material inan organic solution. The polymer solution has a certain viscosity. Inone embodiment, the viscosity of the solution can be greater than 1Pa·s. The polymer material can be in a solid state at room temperature,and can be transparent. The polymer material can include a materialselected from a group consisting of polystyrene, polyethylene,polycarbonate, polymethyl methacrylate (PMMA), polycarbonate (PC),terephthalate (PET), benzo cyclo butene (BCB), and polyalkenamer. Theorganic solution can be selected from a group consisting of ethanol,methanol, acetone, dichloroethane and chloroform. In one embodiment, thepolymer material is PMMA, and the organic solution is ethanol.

The optional step (S212) is similar to the step of (S202).

In step (S213), the at least one drawn carbon nanotube film 141 can beplaced on the layer of the polymer solution directly. When there are twoor more drawn carbon nanotube films 141, the two or more drawn carbonnanotube films 141 can be arranged coplanar and/or stacked. When the TPcarbon nanotube layer 149 includes two or more stacked drawn carbonnanotube films 141, an angle between the aligned directions of thecarbon nanotubes in two adjacent drawn carbon nanotube films 141 rangesfrom above 0° to about 90°. In one embodiment, the TP carbon nanotubelayer 149 includes two drawn carbon nanotube films 141, and the aligneddirection of the carbon nanotube films are offset by 90 degrees.

After the carbon nanotube film 141 is located on the layer of polymersolution, a stacked structure is formed which includes the firstsubstrate 120, the layer of polymer solution and the carbon nanotubefilm 141 in that order.

In step (S214), pressure can be applied with a tool, such as an airknife, to the carbon nanotube film, using airspeeds of 10 meters to 20meters/second to make the polymer material infiltrate into the drawncarbon nanotube film 141 to form the TP carbon nanotube layer 149.Afterwards, the first substrate 120 can be cured by heating it to acertain temperature to evaporate the solvent of the polymer solution.Thus, the polymer material is combined with the carbon nanotube film141, and after the step of curing, a carbon nanotube composite layer canbe acquired. The method for heating the first substrate 120 can beexecuted by placing the first substrate 120 into a furnace or by a UVcuring method, e.g. heating the flexible substrate with UV radiation ata certain energy level to a certain temperature higher than thevolatilization temperature of the solvent. In one embodiment, the curingtemperature is 100° C.

In one embodiment, referring to FIG. 12, a hot-pressing method can befurther adopted to uniformly disperse the polymer into the carbonnanotube film 141. The hot-pressing method includes the following stepsof: placing a substrate 340 with the at least one carbon nanotube film342 and the layer of polymer solution 343 in the hot-press device 370;heating the pressing device of the hot-press device 370; and pressing ofthe first substrate 340 with the at least one carbon nanotube film 342and the layer of polymer solution 343 thereon by the pressing device.

The hot-press device 370 can further include a heating device (notshown) used to heat the pressing device, the layer of polymer solution343, and/or the carbon nanotube film. The shown hot-press device 370 isa hot-press machine with two rollers 372. A temperature of the pressingdevice can range from about 110° C. to about 120° C. The first substrate340 is slowly passing through the two rollers 372. The speed of thefirst substrate 340 is from about 1 millimeter per minute to about 10meters per minute. In other embodiments, a certain pressure is appliedto the first substrate 340, by the heated roller 372. As such, the atleast one carbon nanotube film 342, the polymer solution 343 is presseduniformly disperse the polymer into the at least one carbon nanotubefilm 342. It is to be noted that when the polymer is located between thefirst substrate 340 and at least one carbon nanotube film 342, in theprocess of pressing the first substrate 340, the at least one carbonnanotube film 342 is adhered to the first substrate 340 by the polymer.After curing, the TP carbon nanotube composite layer is formed on thefirst substrate 340. It is understood that the temperature and speed ofthe hot press device can be varied according to need.

The polymer material in the TP carbon nanotube composite layer can makethe TP carbon nanotube composite layer and the first substrate 120combine more firmly. Further, the resistance of the TP carbon nanotubecomposite layer has a nearly linear relationship with distance due tothe polymer material distributed therein. The TP carbon nanotubecomposite layer serves as the first conductive layer 122 in the firstelectrode plate 12.

It is to be understood that, the TP carbon nanotube composite layer alsocan be formed on a separate base, then separated with the base, andplaced on the first substrate. Further, the first conductive layer 122also can comprise a plurality of separately preformed carbon nanotubecomposite layers with a small size located side by side or stacked witheach other.

After step (S20), a step of forming two first electrodes 124 can befurther provided. The first electrodes 124 can be formed by any one ormore of silver, copper and the like metals, carbon nanotube films 141,or conductive silver pastes. In one embodiment, the two first electrodes124 are made of conductive silver paste. One method for making the twofirst silver paste electrodes includes the following steps of: coatingconductive silver paste on opposite ends of the TP carbon nanotube layer149 or on two opposite ends of the first substrate 120 by means ofscreen printing or spraying; and baking the first substrate 120 in anoven for 10-60 minutes at a temperature in a range from about 100° C. toabout 120° C. to solidify the conductive silver paste. The two firstelectrodes 124 are electrically connected to the conductive layer 122.

In step (S30), the second electrode plate 14 includes the secondsubstrate 140, the carbon nanotube composite layer and two secondelectrodes 144. The carbon nanotube composite layer in the secondelectrode plate serves as the second conductive layer 142.

Step (S40) includes the following steps of: (S401) applying aninsulating layer 18 on the second electrode plate 14; (S402) placing thefirst electrode plate 12 on the insulating layer 18, wherein the carbonnanotube composite layer of the first electrode plate 12 is adjacent tothe conductive layer of the second electrode plate 14; (S403) sealingthe first electrode plate 12, the second electrode plate 14, and theinsulating layer 18 with a sealant.

In step (S401), the insulating layer 18 can be made of, for example,insulative resin or any other insulative transparent material. Theinsulating layer 18 can be formed by coating a layer of insulativematerial on the edges of the second conductive layer 144 or the secondsubstrate 140. It is understood that the insulating layer 18 could beplaced on the conductive layer of the second electrode plate 14 or thefirst substrate 120.

In step (S402), the two first electrodes 124 in the first electrodeplate 12 and the two second electrodes 144 in the second electrode plate12 are set at angles to each other. In step (S403), the sealant can becoated on the peripheries of the first electrode plate 12, the secondelectrode plate 14, and the insulating layer 18.

Furthermore, the method for making the touch panel 10 can furtherinclude the steps of: coating a layer of slurry comprising a pluralityof dot spacers 16 on the portion of the surface of the first electrodeplate 12 and/or the second electrode plate 14 having the conductivelayer thereon; and drying the layer of slurry resulting in a pluralityof dot spacers 16. The dot spacers 16 can be made of insulative resinsor can be other insulative materials. Insulation between the firstelectrode plate 12 and the second electrode plate 14 is provided by theinsulating layer 18 and the plurality of dot spacers 16. It is to beunderstood that the dot spacers 16 are optional, especially when thesize of the touch panel 10 is relatively small.

In other embodiments, a continuous operation device configured forcontinuously preparing the electrode plate 12, and 14 can be adopted.

Method for Continuously Preparing the Electrode Plates

Referring to FIG. 13, the continuous operation device 200 includes afirst shaft roller 202, a second shaft roller 204, a third shaft roller206, a container 208, a platform 210, a tubular furnace 212, a tractiondevice 214, an air knife 216, a removal device 230, and a laser 232. Thefirst shaft roller 202, the second shaft roller 204, and the third shaftroller 206 are located separately and the axes thereof are along a samedirection. The third shaft roller 206 and the traction device 214 arelocated on two ends of the tubular furnace 212. The air knife 216 islocated between the third shaft roller 206 and the tubular furnace 212.The container 208 has an opening and is located below the second shaftroller 204, and part of the second shaft roller 204 is located in thecontainer 208. The removal device 230 is adjacent to the second shaftroller 204 and a certain distance is formed between one end of theremoval device 230 and the second shaft roller 204. A flexible substrate218 is wound on the first shaft roller 202. The container 208 is filledwith a polymer solution 220.

The method for making the first electrode plate and the second electrodeplate using the continuous operation device includes the following stepsof: (S220) passing the flexible substrate 218 around the second shaftroller 204, the third shaft roller 206 and the tubular furnace 212 insequence to connect the flexible substrate 218 with the traction device214 and forming a layer of polymer solution 226 on a surface of theflexible substrate 218; (S221) securing a carbon nanotube array 222 onthe platform 210, drawing a drawn carbon nanotube film 224 from thecarbon nanotube array 222 and adhering one surface of the drawn carbonnanotube film to the layer of polymer solution 226 on the surface of theflexible substrate 218; (S223) drawing the flexible substrate 218 withthe layer of polymer solution 226 and the drawn carbon nanotube film 224thereon by the traction device 214 at a certain speed along a directionparallel to the axis of the tubular furnace 212 to pass through thetubular furnace 212, thereby forming the carbon nanotube composite layer228; and (S224) cutting the flexible substrate 218 with the carbonnanotube composite layer 228 thereon to form the electrode plate.

In step (S220), since part of the second shaft roller 204 is in thecontainer 208, the polymer solution 220 in the container 208 can adhereon the surface of the flexible substrate 218 to form a layer of polymersolution 226. The removal device 230 maintains the thickness of thelayer of polymer solution 226 on the substrate 218. The removal devicecan be a scrapper that is maintained a certain distance from thesubstrate 218.

In step (S221), the carbon nanotube array 222 can be a super-alignedcarbon nanotube array. After the drawn carbon nanotube film 224 is drawnfrom the carbon nanotube array 222 and before the drawn carbon nanotubefilm 224 contacts with the layer of polymer solution 226, a laser device232 can be used to irradiate the drawn carbon nanotube film 224 toincrease the light transmittance of the drawn carbon nanotube film 224as described above.

In step (S222), since the air knife 216 is located between the thirdshaft roller 206 and the tubular furnace 212, when the drawn carbonnanotube film passes below the air knife 216, wind produced by the airknife 216 applies a certain pressure to the drawn carbon nanotube film224, the polymer solution 220 of the layer of polymer solution 226infiltrates into the drawn carbon nanotube film 224. It is understoodthat any device that applies air pressure can be used in place of theair knife. The polymer solution 220 cures in the heat of the tubularfurnace 212 when the flexible substrate with the drawn carbon nanotubefilm thereon passes therethrough. Thereby, the TP carbon nanotubecomposite layer 228 forms on the flexible substrate 218.

The above-described method can realize continuous production of theelectrode plates 12, 14; which is conducive to making low-cost highlyefficient touch panels.

Liquid Crystal Display Screen

Referring further to FIG. 14, one liquid crystal display screen 300 isprovided and includes an upper component 310, a bottom component 320opposite to the upper component 310, and a liquid crystal layer 330located between the upper component 310 and the bottom component 320.The liquid crystal layer 330 includes a plurality of cigar shaped liquidcrystal molecules. Understandably, the liquid crystal layer 330 can alsobe made of other conventional suitable materials, such as alkyl benzoicacid, alkyl cyclohexyl acid, alkyl cyclohexyl-phenol, phenylcyclohexane, and so on. A thickness of the liquid crystal layer 330ranges from about 1 micrometer to about 50 micrometers. In oneembodiment, a thickness of the liquid crystal layer 330 is about 5micrometers. The material of the liquid crystal layer 310 is phenylcyclohexane.

The upper component 310 can include a touch panel (including any touchpanel described herein), a first polarizer 312, and a first alignmentlayer 314 in sequence. In one embodiment, the touch panel is touch panel10 described above. The first polarizer 312 is located between the touchpanel 10 and the first alignment layer 314 and used to polarize lightpassing through the liquid crystal layer 330. A plurality of firstgrooves (not shown) parallel to each other are located on a surface ofthe first alignment layer 314. The plurality of first grooves is used tomake the liquid crystal molecules align along a same direction. Thefirst alignment layer 314 is adjacent to the liquid crystal layer 330.

A material of the first polarizer 312 can be conventional polarizingmaterial, such as dichroism organic polymer materials. In someembodiments, the material of the first polarizer 312 can be iodinematerial or dyestuff material. The first polarizer 312 also can be anordered carbon nanotube film having a plurality of carbon nanotubes arearranged along a same direction. The carbon nanotube film can be thedrawn carbon nanotube film. A thickness of the first polarizer 312 canrange from about 1 micrometer to about 0.5 millimeters.

Since the carbon nanotubes absorb electromagnetic waves like a blackbody, and the carbon nanotubes have uniform absorption ability anywherein the electromagnetic spectrum, the carbon nanotube film also has auniform polarization property throughout the electromagnetic spectrum.When the light beams are transmitted into the carbon nanotube film, someof the light beams parallel to the carbon nanotubes are absorbed by thecarbon nanotube film, and the beams of light perpendicular to the carbonnanotubes are transmitted through the carbon nanotube film. Thetransmitted light is linearly polarized light. Thus the carbon nanotubefilm can be used as a polarizer. In some embodiments, the firstpolarizer 312 includes a plurality of carbon nanotubes arranged along asame direction, thus the first polarizer 312 has a good conductiveproperty, and can be used as the upper electrode of the liquid crystaldisplay screen 300. That is, the first polarizer 312 can act as both apolarizer and an upper electrode of the liquid crystal display screen300 as can be see in FIG. 14. Thus an upper electrode and the polarizercan be combined to acquire a liquid crystal display screen 300 having alow thickness, simple structure, and low cost. This can also enhance theefficiency of usage of an associated backlight since a layertherebetween can be eliminated.

Material of the first alignment layer 314 can be selected from a groupconsisting of polystyrenes and derivatives of the polystyrenes,polyimides, polyvinyl alcohols, polyesters, epoxy resins, polyurethanes,other polysilanes and CNTs. The first grooves of the first alignmentlayer 314 can be formed by a rubbing method, a tilt deposition method,or a micro-grooves treatment method, a SiOx-depositing method, and soon. In one embodiment, a material of the first alignment layer 314 ispolyimide and a thickness thereof ranges from about 1 micrometer toabout 50 micrometers.

It is to be understood that, in the drawn carbon nanotube film, thecarbon nanotubes are aligned along the same direction and a groove canbe formed by two adjacent carbon nanotubes. Thus, in another embodiment,the polarizer 312 made of drawn carbon nanotube film can be used as thefirst alignment layer 314, and thus the drawn carbon nanotube film willact as the alignment layer, the electrode and the polarizer. In otherembodiments, the drawn carbon nanotube film is used as the alignmentlayer 314, while still employing a first polarizer 312. The drawn carbonnanotube films 141 are aligned along a same direction, and the carbonnanotubes in the first alignment layer 314 are aligned substantiallyalong the same direction.

The bottom component 320 includes a second alignment layer 328, a thinfilm transistor panel 322, and a second polarizer 329 in sequence. Thesecond alignment layer 328 is adjacent to the liquid crystal layer 330.The thin film transistor panel 322 is located between the secondalignment layer 328 and the second polarizer 329. A plurality of secondgrooves (not shown) parallel to each other and perpendicular to thefirst grooves can be located on a surface of the second alignment layer328 facing the liquid crystal layer 330.

Material of the second polarizer 329 can be conventional polarizingmaterial, such as dichroism organic polymer materials. In someembodiments, the material of the first polarizer 110 can be iodinematerial or dyestuff material. A thickness of the second polarizer 329ranges from about 1 micrometer to about 0.5 millimeters. The secondpolarizer 329 is used to polarize the light beams emitted from the lightguide plate (not shown) located on the surface of the display screen 300facing away from the thin film transistor panel 322, and thus acquirepolarized light beams along a same direction. In one embodiment, thesecond polarizer 329 includes at least one layer of the drawn carbonnanotube film, the carbon nanotubes in the second polarizer 329 aresubstantially aligned along a same direction.

The material of the second alignment layer 328 can be the same as thatof the first alignment layer 314. An alignment direction of the firstgrooves is perpendicular to an alignment direction of the secondgrooves. The second grooves of the second alignment layer 328 are usedto make the liquid crystal molecules align along a same direction. Sincethe alignment direction of the first grooves is perpendicular to thealignment direction of the second grooves, the alignment direction ofthe liquid crystal molecules differ by 90 degrees between the firstalignment layer 314 and the second alignment layer 328 to play a role ofshifting the light beams polarized by the second polarizer 329 90degrees. In one embodiment, material of the second alignment layer 328is polyimide and a thickness thereof ranges from about 1 micrometer to50 micrometers. In another embodiment, the second alignment layer 328can include at least one layer of the drawn carbon nanotube film as theabove-described first alignment layer 314. The drawn carbon nanotubefilms 141 are aligned along a same direction, and the carbon nanotubesin the second alignment layer 328 are aligned substantially along thesame direction. When the first and second alignment layers 314, 328 bothinclude the drawn carbon nanotube films 141, the carbon nanotubes in thefirst alignment layer 314 are perpendicular to the carbon nanotubes inthe second alignment layer 328.

In one embodiment, the aligned direction of the carbon nanotubes in thefirst alignment layer 314 is the same with the aligned direction of thecarbon nanotubes in the first polarizer 312, and is defined as the thirddirection. The aligned direction of the carbon nanotubes in the secondalignment layer 328 is the same with the aligned direction of the carbonnanotubes in the second polarizer 329, and is defined as the fourthdirection. The third direction is perpendicular to the fourth direction.The third and forth direction may or my not correspond to the first andsecond directions.

Referring to FIG. 15, the thin film transistor panel 322 includes athird substrate 324 having a first surface 3242 and a second surface3244, a plurality of thin film transistors 326 located on the firstsurface 3242 of the third substrate 324, a plurality of pixel electrodes332, a plurality of source lines 334, a plurality of gate lines 336, anda display driver circuit (not shown). The plurality of thin filmtransistors 326 corresponds to the plurality of pixel electrodes 332.The plurality of thin film transistors 326 is connected to the displaydriver circuit by the source lines 334 and gate lines 336. The pluralityof thin film transistors 326 and the plurality of the pixel electrodes332 can be located on the first surface 3242 of the third substrate 324in a matrix.

The thin film transistors 326, pixel electrodes 332, source lines 334,and gate lines 336 are located on the first surface 3242 of the thirdsubstrate 324. The source lines 334 are spaced with each other andarranged parallel along an X direction. The gate lines 336 are spacedwith each other and arranged parallel along a Y direction. The Xdirection is perpendicular to the Y direction. Thus, the first surface3242 of the third substrate 324 is divided into a matrix of grid regions338. The pixel electrodes 332 and the thin film transistors 326 areseparately located in the grid regions 338. The pixel electrodes 332 arespaced from each other. The thin film transistors 326 are spaced fromeach other. Each grid region 338 contains one thin film transistor 326and one pixel electrode 332, and the pixel electrode 332 is electricallyconnected to a drain electrode of the thin film transistor 326. Eachsource electrode of the thin film transistor 326 is electricallyconnected to the source line 334. In some embodiments, the sourceelectrodes of each line along the X direction are electrically connectedwith one of the source lines 334 adjacent to the source electrodes ofthe corresponding line. Each gate electrode of the thin film transistors326 are electrically connected with the gate lines 336. Morespecifically, the gate electrodes of each line along the Y direction areelectrically connected with one gate line 336 adjacent thereto.

The display driver circuit is electrically connected to the source lines334 and the gate lines 336 to control the thin film transistors 326. Thedisplay driver circuit can be integrated on the third substrate 324 toform an integrated circuit board.

The pixel electrodes 332 are conductive films made of a conductivematerial. When the pixel electrodes 332 are used in the liquid crystaldisplay screens, the materials of the pixel electrodes 332 can beselected from the group consisting of indium tin oxide (ITO), antimonytin oxide (ATO), indium zinc oxide (IZO), conductive polymer, andmetallic carbon nanotubes. An area of each pixel electrodes 332 can bein a range from about 10 square micrometers to about 0.1 squaremillimeters. In one embodiment, the material of the pixel electrodes 332is ITO, and the area thereof is about 0.05 square millimeters.

The materials of the source lines 334 or the gate lines 336 areconductive, and can be selected from the group consisting of metal,alloy, silver paste, conductive polymer, or metallic carbon nanotubewires. The metal or alloy can be selected from the group consisting ofaluminum (Al), copper (Cu), tungsten (W), molybdenum (Mo), gold (Au),titanium (Ti), neodymium (Nd), palladium (Pd), cesium (Cs), andcombinations thereof. A width of the source lines 334 and the gate lines336 can be in the range from about 0.5 nanometers to about 100micrometers. In one embodiment, the material of the source lines 334 andthe gate lines 336 is Al, and the width of the source lines 334 and thegate lines 336 is about 10 micrometers.

The thin film transistor 326 can have a top gate structure or a bottomgate structure. Referring further to FIG. 16, in one embodiment, thethin film transistor 326 has a bottom gate structure and includes asemiconducting layer 3260, a source electrode 3262, a drain electrode3264, an insulating layer 3266, and a gate electrode 3268.

A pixel insulating layer 342 can be further disposed on the thin filmtransistor 326. The pixel insulating layer 342 covers the thin filmtransistor 326 and defines a through hole 327 to expose the drainelectrode 3264 of the thin film transistor 326. The pixel electrode 332covers the entire grid region 338 and the thin film transistor 326therein, and electrically connects to the drain electrode 3264 throughthe through hole 327. Other part of the thin film transistor 326 exceptthe drain electrode 3264 is insulated from the pixel electrode 332 bythe pixel insulating layer 342. The material of the pixel insulatinglayer 342 can be a rigid material such as silicon nitride (Si3N4) orsilicon dioxide (SiO2), or a flexible material such as polyethyleneterephthalate (PET), benzocyclobutenes (BCB), or acrylic resins.

The semiconducting layer 3260 is electrically connected to the sourceelectrode 3262 and the drain electrode 3264. The gate electrode 3268 isinsulated from the source electrode 3262, the drain electrode 3264 andthe gate electrode 3268 by the insulating layer 3266. The gate electrode3268 is located on the first surface 3242 of the third substrate 324.The insulating layer 3266 covers the gate electrode 3268. Thesemiconducting layer 3260 is located on the insulating layer 3266, andinsulated from the gate electrode 3268 by the insulating layer 3266. Thesource electrode 3262 and the drain electrode 3264 are spaced apart fromeach other and located on the semiconducting layer 3260. The pixelelectrode 332 is electrically connected with the drain electrode 3264 ofthe thin film transistor 326. Each source electrode 3262 of the thinfilm transistor 326 is electrically connected with one source line 334.

The thin film transistor 326 includes amorphous silicon-based thin filmtransistors, polysilicon-based thin film transistors, organic thin filmtransistors, zinc oxide-based thin film transistors, and CNT-based thinfilm transistors. In one embodiment, the thin film transistor 326 is aCNT-based thin film transistor, and the semiconducting layer 3260thereof includes a TFT carbon nanotube layer. The TFT carbon nanotubelayer includes a plurality of carbon nanotubes. The carbon nanotubes canbe single-walled carbon nanotubes or double-walled carbon nanotubes. Inone embodiment, diameters of the carbon nanotubes are less than 10nanometers. The length of the semiconducting layer 3260 can range fromabout 1 micrometer to 100 micrometers, the width of the semiconductinglayer 3260 can range from about 1 micrometer to 1 millimeter, and athickness of the semiconducting layer 3260 can range from about 0.5nanometers to 100 micrometers.

The TFT carbon nanotube layer includes one or more carbon nanotube films141 described herein. The carbon nanotube film includes a plurality ofcarbon nanotubes, and the carbon nanotubes can be uniformly distributedtherein. The carbon nanotubes in the TFT carbon nanotube layer are allsemiconducting carbon nanotubes or at least a large part thereof aresemiconducting carbon nanotubes. In one embodiment, the carbon nanotubesin the TFT carbon nanotube layer are all semiconducting carbonnanotubes.

In one embodiment, the TFT carbon nanotube layer includes a carbonnanotube film having a plurality of carbon nanotubes. Referring to FIG.17, the carbon nanotubes in the carbon nanotube film can be arrangedalong a preferred orientation extending from the source electrode 3262to the drain electrode 3264. The carbon nanotubes are parallel with eachother, generally equal in length and combined side by side by van derWaals attractive force therebetween. The length of the film can be equalto the lengths of the carbon nanotubes. In one embodiment, at least onecarbon nanotube will span the entire length of the carbon nanotube film,a carbon nanotube segment film. The length of the carbon nanotubesegment film is only limited by the lengths of the carbon nanotubes. Inone embodiment, the length of the semiconducting layer 3260 is 50micrometers, a width of the semiconducting layer 3260 is 300micrometers, and a thickness of the semiconducting layer 3260 is 5nanometers. A channel is defined in the semiconducting layer 3260 at aregion between the source electrode 3262 and the drain electrode 3264.In one embodiment, the length of the channel is about 5 micrometers, awidth of the channel ranges from about 40 micrometers to 100micrometers. Each end of the carbon nanotubes are connected to thesource electrode 3262 or the drain electrode 3264.

Since the carbon nanotubes in the semiconducting layer 3260 are arrangedalong the preferred direction extending from the source electrode 3262to the drain electrode 3264 and the semiconducting carbon nanotubes haveexcellent semiconducting properties, the paths for the carriers totravel in the semiconducting layer 3260 are minimum, and the carriermobility of the thin film transistor 326 is relatively high. Because ofthis, it is possible to enhance the display characteristic of the liquidcrystal display screen, such as response speed.

The thin film transistor panel 322 is used as a pixel drive element foreach of the pixel points. The pixel point is an image unit of the liquidcrystal display screen 300 and a plurality of image units can form animage displaying on the liquid crystal display screen 300. When thefirst polarizer 312 is used as the upper electrode of the liquid crystaldisplay screen 300, and a voltage is applied to the pixel electrodes andthe first polarizer 312, the liquid crystal molecules in the liquidcrystal layer 330 between the first alignment layer 312 and the secondalignment layer 328 align along a same direction to make the light beamspolarized by the second polarizer 329 irradiate on the first polarizer312 directly without rotation, and the polarized light beams cannot passthrough the first polarizer 312. Without a voltage applied to the pixelelectrode and the first polarizer 312, the polarized light beams rotatedby the liquid crystal molecules can pass through the first polarizer312.

Referring to an embodiment shown in FIG. 18, the liquid crystal displayscreen 300 further includes the first controller 30, the centralprocessing unit (CPU) 40, and the second controller 50. The firstcontroller 30, the CPU 40, and the second controller 50 are electricallyinterconnected. The touch panel 302 is connected to the first controller30 by an external circuit. The second controller 50 is electricallyconnected to the display driver circuit of the thin film transistorpanel 322 of the bottom component 320.

In operation, a voltage of 5V is applied to each of the twofirst-electrodes 124 of the first electrode plate 12 and to each of thetwo second electrodes 144 of the second electrode plate 14. A useroperates the display by pressing the first electrode plate 12 of thetouch panel 10 with a finger, a pen/stylus 60, or the like whilevisually observing the display of the liquid crystal display screen 300through the touch panel 10. This pressing causes a deformation of thefirst electrode plate 12. The deformation of the first electrode plate12 causes a connection between the first conductive layer 122 and thesecond conductive layer 142 at a touch point 70. Voltage changes in thefirst direction of the first conductive layer 122 and the seconddirection of the second conductive layer 142 can be detected by thefirst controller 30. Then the first controller 30 transforms the voltagechanges into coordinates of the touch point 70, and sends thecoordinates of the touch point 70 to the CPU 40. The CPU 40 then sendsout commands according to the coordinates of the touch point 70 andfurther controls the display driver circuit of the thin film transistorpanel 322 of the bottom component 320.

Method for Making Liquid Crystal Display Screen

Referring to FIG. 19, a method for making the liquid crystal displayscreen 300, according to one embodiment, includes the following stepsof: (S60) preparing an upper component 310 comprising a touch panel 10,a first polarizer 312, and a first alignment layer 314; (S70) preparinga bottom component 320 comprising a second alignment layer 328, a thinfilm transistor panel 322, and a second polarizer 329; and (S80) placinga liquid crystal layer 330 between the first alignment layer 314 of theupper component 310 and the second alignment layer 328 of the bottomcomponent 320.

Referring to FIG. 20, step (S60) can further include the following stepsof: (S601) preparing the touch panel 10; (S602) forming a firstpolarizer 312 on a surface of the touch panel 302; and (S603) forming afirst alignment layer 314 on a surface of the first polarizer 312.

In step (S602), the first polarizer 312 is located on the second surface1404 of the second substrate 140. In some embodiments, the polarizer 312includes a TP carbon nanotube layer 149 and/or a TP carbon nanotubecomposite layer. The polarizer 312 will include a plurality of drawncarbon nanotube films 141 coplanar and/or stacked with each other. Thecarbon nanotubes in the plurality of drawn carbon nanotube films 141 arearranged along a same direction. A thickness of the first polarizer 312ranges from about 100 micrometer to about 0.5 millimeters.

Step (S603) can be executed by a method including a screen printingmethod or a spraying method. In one embodiment, the first alignmentlayer 314 is formed by spraying a layer of polyimide on the surface ofthe first polarizer 312 facing away from the touch panel 302. The firstalignment layer 314 can include a plurality of first grooves formedthereon. The first grooves of the first alignment layer 314 can beformed by a rubbing method, a tilt deposition method, or a micro-groovestreatment method, and so on. Step (S603) can be optional.

Referring to FIG. 21, step (S70) can include the following steps of:(S701) preparing a thin film transistor panel 322, the thin filmtransistor panel 322 includes a third substrate 324 having the firstsurface 3242 and the second surface 3244, and a plurality of thin filmtransistors 326 located on the first surface 3242 of the third substrate324; (S702) applying a second alignment layer 328; and (S703) placing asecond polarizer 329 on the second surface 3244 of the third substrate324 of the thin film transistor panel 322.

In step (S701), each thin film transistor 326 includes a semiconductinglayer with a plurality of carbon nanotubes therein. The size and thematerial of the third substrate 324 can be the same as that of thesecond substrate 140. The thin film transistor array 326 can includeamorphous silicon-based thin film transistors, polysilicon-based thinfilm transistors, organic thin film transistors, or zinc oxide-basedthin film transistors. The method for forming the thin film transistorcan be selected from among known conventional methods. In oneembodiment, the thin film transistor array 326 includes carbon nanotubebased thin film transistors.

When the thin film transistor array 326 includes carbon nanotube basedthin film transistors, the thin film transistor panel 322 can beprepared by the following steps. Referring to FIG. 22, firstly, thethird substrate 324 is supplied and a conductive layer 331 is formed onthe first surface 3242 of the third substrate 324 and the conductivelayer 331 is then patterned to form a plurality of source lines 334, anda plurality of gate electrodes 3268. Secondly, a first insulating layer333 is formed to cover the source lines 334 and the gate electrodes3268. Thirdly, a plurality of semiconducting layers 3260 are formed onthe surface of the first insulating layer 333. Fourthly, a plurality ofgate lines 336 parallel with each other and spaced for a certaindistance are formed, and adjacent two gate lines 336 and adjacent twosource lines 334 constitute a grid region 338. The source electrode 3262and the drain electrode 3264 are then separately formed on eachsemiconducting layer 3260, and each source electrode 3262 iselectrically connected to the gate lines 336. Fifthly, a secondinsulating layer 335 covers the gate lines 336, the source electrodes3262, the drain electrodes 3264 and the semiconducting layers 3260.Then, a plurality of through holes 327 are formed in the insulatinglayer 335. Finally, pixel electrodes 332 are formed and the pixelelectrode 332 is electrically connected to the drain electrode 3264 ineach grid region 338.

In the first step, the size and/or the material of the third substrate324 can be the same as that of the second substrate 140. In the thirdstep, each semiconducting layer 3260 corresponds to a gate electrode3268.

The materials of the source lines 334 and the gate electrodes 3368 areconductive, and can be selected from the group consisting of metal,alloy, ITO, ATO, silver paste, conductive polymer, or metallic carbonnanotubes. The metal or alloy can be selected from the group consistingof aluminum (Al), copper (Cu), tungsten (W), molybdenum (Mo), gold (Au),titanium (Ti), neodymium (Nd), palladium (Pd), cesium (Cs), andcombinations thereof. The methods for making the source lines 434 andthe gate electrodes 3368 vary according to the kinds of the materialused. When the material of the source lines 334 and the gate electrodes3368 is metal, alloy, ITO or ATO, the method for forming the sourcelines 334 and the gate electrodes 3368 can be an evaporation method, asputtering method, a deposition method, a masking method or an etchingmethod. When the material of the source lines 334 and the gateelectrodes 3368 is silver paste, conductive polymer, or metallic carbonnanotubes, the source lines 334 and the gate electrodes 3368 can beprinted or adhered directly on the first surface of the third substrate324. The thickness of the source lines 334 and the gate electrodes 3368can range from about 0.5 nanometers to about 100 micrometers. In oneembodiment, the material of the conductive layer 331 is metal, and themethod for forming the source lines 334 and the gate electrodes 3368includes a deposition method, a masking method and an etching method.

In a second step, a material of the first insulating layer 333 can be arigid material, such as silicon nitride or silicon oxide, or a flexiblematerial, such as benzocyclobutene (BCB), polyester or acrylic resin.The method for forming the first insulating layer 333 can include adeposition method or a printing method. A thickness of the firstinsulating layer 333 can range from about 0.5 nanometers to about 100micrometers. In one embodiment, the material of the first insulatinglayer 333 is silicon nitride, the first insulating layer 333 is formedby a plasma chemical vapor deposition method, and a thickness of thefirst insulating layer 333 is about 1 micrometer.

A third step can include the following steps of: supplying at least onecarbon nanotube film including a plurality of carbon nanotubes arrangedalong a same direction; placing the at least one carbon nanotube film onthe surface of the first insulating layer 333 to form a carbon nanotubelayer; and patterning the carbon nanotube layer to form a plurality ofsemiconducting layers 3260. When the semiconducting layers 3260 have analmost same size as the carbon nanotube film, each carbon nanotube filmcan be patterned to form one semiconducting layer 3260. When the size ofthe carbon nanotube film is larger than the semiconducting layers 3260,each carbon nanotube film can be patterned to form two or moresemiconducting layers 3260. The method for patterning includes anetching method. In one embodiment, the carbon nanotube film includes aplurality of carbon nanotubes arranged along a same direction. Thecarbon nanotubes are parallel to the surface of the carbon nanotubefilm. The carbon nanotube film can include one or more carbon nanotubesegments. The carbon nanotubes in the carbon nanotube segment areparallel with each other, have almost equal lengths and are combinedside by side by van der Waals attractive force therebetween. The lengthof the carbon nanotube film can be equal to the length of the carbonnanotubes. Such that at least one carbon nanotube will span the entirelength of the carbon nanotube film (e.g. a carbon nanotube segmentfilm). The length of the carbon nanotube film is only limited by thelength of the carbon nanotubes. The carbon nanotubes can be selectedfrom a group consisting of single-walled carbon nanotubes, double-walledcarbon nanotubes or combination thereof. A diameter of the carbonnanotubes ranges from about 0.5 nanometers to 10 nanometers. Each of theone or more carbon nanotube segments can correspond to one of thesemiconducting layer 3260. When the size of the carbon nanotube segmentis larger than the semiconducting layers 3260, each carbon nanotubesegment can be patterned, such as by etching, to form two or moresemiconducting layer 3260.

The method for patterning the carbon nanotube layer to form a pluralityof semiconducting layers 3260 can include a laser etching method or aplasma etching method.

In a fourth step, the material of the gate lines 336, the sourceelectrode 3262 and the drain electrode 3264 and the method for makingthe gate lines 336, the source electrode 3262 and the drain electrode3264 can be the same as that of the source lines 334 and the gateelectrodes 3368. When the semiconducting layer 3260 includes a pluralityof carbon nanotubes arranged along a same direction, the carbonnanotubes extend from the source electrodes 3262 to the drain electrodes3264.

It can be understood that to acquire the semiconducting layer 3260having a better semiconducting property, a step of eliminating themetallic carbon nanotubes in the carbon nanotube layer 3260 can befurther provided. In one embodiment, a voltage is applied between thesource electrode 3262 and the drain electrode 3264, to break down themetallic carbon nanotubes in the carbon nanotube layer, thus asemiconducting layer 3260 free of metallic carbon nanotubes therein isachieved. The voltage is in a range from about 1 to about 1000 volts(V). In other embodiments, the carbon nanotube layer can be irradiatedwith a hydrogen plasma, microwave, terahertz (THz), infrared (IR),ultraviolet (UV), or visible light (Vis), to break down the metalliccarbon nanotubes in the carbon nanotube layer, to achieve asemiconducting layer 360 free of metallic carbon nanotubes therein.

In a fifth step, a material, a thickness and a method for forming thesecond insulating layer 335 can be the same as that of the firstinsulating layer 333. The method for forming the through holes 327 canbe done by an etching method or an ion bombardment method. Because thesecond insulating layer 335 at the through hole 327 is eliminated, aconductive channel for the drain electrode 3264 communicating withexternal space can be formed by the through hole 327.

The pixel electrodes 332 are conductive films and can be selected from agroup consisting of indium tin oxide (ITO) layers, antimony tin oxide(ATO) layer, indium zinc oxide (IZO) layers or metallic carbon nanotubelayers, and other transparent layers. The area of the pixel electrodes332 is smaller than that of the grid region 338. The pixel electrodes332 are electrically connected to the drain electrodes 3264. The area ofthe pixel electrodes 332 can range from about 10 square micrometers toabout 0.1 square millimeters. In one embodiment, the material of thepixel electrodes 332 is ITO, and the area thereof is about 0.05 squaremillimeters.

A method for making the pixel electrodes 332 includes the followingsteps of: forming a conducting layer (not shown) on the surface of thesecond insulating layer 335 on the third substrate 324; etching theconducting layer to form the pixel electrodes 332 in the grid regions338; and making the pixel electrodes 332 electrically connected to thedrain electrodes 3264 by the through holes 327. The method for etchingthe conducting layer can include a laser etching method, a plasmaetching method, and other methods.

The method for forming the conductive layer can include an evaporationmethod, a sputtering method, or a deposition method. During the processof forming the conductive layer, the through holes 327 are filled withthe material of the conductive layer. Thus, the drain electrode 3264 iselectrically connected to the conductive layer, and after etching, thedrain electrode 3264 is electrically connected to the pixel electrodes332.

Step (S702) can be executed by the same methods for applying the firstalignment layer 314 on the first polarizer 312. Step (S702) is optional.

In step (S703), the second polarizer 329 can be conventional polarizingmaterial, such as dichroism organic polymer materials. In someembodiments, the material of the first polarizer 110 can be iodinematerial or dyestuff material. The second polarizer 329 can be placed onthe second surface of the third substrate 324 by a transparent adhesive.A polarization direction of the polarized light beams passing throughthe second polarizer 329 is perpendicular to that passing through thefirst polarizer 312. A thickness of the second polarizer 329 ranges fromabout 1 micrometer to about 0.5 millimeters. When a polarized light isutilized, the second polarizer 329 can be omitted.

Step (S80) can be executed by the following steps of: applying theliquid crystal material on the surface of the first alignment layer 314of the upper component 310 or the second alignment layer 328 of thebottom component 320; locating the other alignment layer adjacent to theliquid crystal layer 330; and securing the upper component 310 and thebottom component 320. In one embodiment, a drop-tube is used to supplythe liquid crystal material. The liquid crystal layer 330 can include aplurality of cigar shaped liquid crystal molecules. The alignmentdirection of the first grooves is perpendicular to that of the secondgrooves. The silicon sulfide rubber can be use to coat on the edge ofthe upper component 310 and the bottom component 320.

Step (S80) also can be executed by the following steps of: placing theupper component 310 and the bottom component 320 spaced and parallelwith each other, the first alignment layer 314 is opposite to the secondalignment layer 328; sealing the edges of the upper component 310 andthe bottom component 320; and supplying an amount of liquid crystalmaterial between the upper component 310 and the bottom component 320through a small hole.

Further, in order to maintain enough spacing between the upper component310 and the bottom component 320, a plurality of spacers (not shown) isplaced therebetween. The size and the material of the spacers can beselected based on users' specific needs. In one embodiment, a pluralityof polyethylene (PE) balls are dispersed in the ethanol, and the ethanolcontaining the PE balls are put between the upper component 310 and thebottom component 320. After the ethanol has evaporated, the PE ballsbetween the upper component 310 and the bottom component 320 are used asthe spacers. The diameter of the PE balls can range from about 1 toabout 10 micrometers.

The liquid crystal display screen 300 can be used in electronicapparatuses, such as personal computer systems (e.g., desktops, laptops,tablets or handhelds). The electronic apparatuses may also correspond topublic computer systems such as information kiosks, automated tellermachines (ATM), point of sale machines (POS), industrial machines,gaming machines, arcade machines, vending machines, airline e-ticketterminals, restaurant reservation terminals, customer service stations,library terminals, learning devices, and the like. The CPU of theelectronic apparatuses and the CPU 40 of the liquid crystal displayscreen 300 can be integrated.

Further, to keep the distance from the upper component 310 to the bottomcomponent 320, a plurality of spacers (not shown) can be located betweenthe upper component 310 and the bottom component 320 when the liquidcrystal display screen had a large scale. In one embodiment, a diameterof the spacers is in the range from about 1 micron to about 10 microns.

It is to be understood that the liquid crystal display screen 300 canfurther include other elements such as color filters, black matrix,backlight unit, TFT driving circuit unit, and so on. The color filtersare located below the first polarizer 312 for providing different colorof lights. The black matrix is formed on the lower surface of the secondsubstrate 140. The backlight unit is located below the second polarizer329 for providing light. The display driver circuit is connected to theTFTs for driving the TFT panel 322. The black matrix may be located onthe lower surface of the second substrate 140 in a matrix arrangement.The black matrix may divide the surface of the second substrate 140 intoa plurality of cell areas where the color filters are to be formed andto prevent light interference between adjacent cells. The color filtermay include red, green, and blue tricolors.

It is to be understood that the bottom component can further include acarbon nanotube layer configured for both polarizing light and aligningliquid crystals. The carbon nanotube layer comprises a plurality ofcarbon nanotubes substantially arranged along a primary direction.

It is to be understood that there are two kinds of carbon nanotubesmetallic carbon nanotubes and semiconducting carbon nanotubes. The typeis determined by the arrangement of the carbon atoms therein. The carbonnanotube structure or carbon nanotube film may contain both kinds of thecarbon nanotubes. In the present application, only in the semiconductinglayers 3260, almost all or at least a large part of the carbon nanotubesare semiconducting carbon nanotubes. In other elements that includingcarbon nanotubes of the touch panel and the liquid crystal displayscreen, the majority of the carbon nanotubes are metallic carbonnanotubes.

The touch panels and the liquid crystal display screens can have at manyadvantages. Firstly, because the carbon nanotube film or the carbonnanotube composite film has superior toughness, high mechanicalstrength, and uniform conductivity, the touch panel and the liquidcrystal display screen using the same adopting the carbon nanotube filmor the carbon nanotube composite film are durable. Secondly, a flexibletouch panel and a flexible liquid crystal display screen can be acquiredby combining the carbon nanotube film or the carbon nanotube compositefilm with a flexible substrate. Thirdly, since the carbon nanotubes haveexcellent electricity conductive property, a carbon nanotube film formedby a plurality of carbon nanotubes uniformly distributed therein, has auniform resistance distribution; and thus the touch panel and the liquidcrystal display screen using the same have an improved sensitivity andaccuracy. Fourthly, carbon nanotube films can have a high transparency,thereby promoting improved brightness of the touch panel and the liquidcrystal display screen using the same. Fifthly, the pulling method forfabricating the carbon nanotube film is simple, and the adhesive carbonnanotube film can be located directly on the substrate. As such, themethod for fabricating a drawn carbon nanotube film is suitable for themass production of touch panels and display device using the same andreduces the cost thereof.

It is also to be understood that above description and the claims drawnto a method may include some indication in reference to certain steps.However, the indication used is only to be viewed for identificationpurposes and not as a suggestion as to an order for the steps.

Finally, it is to be understood that the above-described embodiments areintended to illustrate rather than limit the disclosure. Variations maybe made to the embodiments without departing from the spirit of theinvention as claimed. Any element discussed with any embodiment isenvisioned to be able to be used with the other embodiments. Theabove-described embodiments illustrate the scope of the disclosure butdo not restrict the scope of the disclosure.

1. A method for fabricating a touch panel, the method comprising:providing a first substrate and a second substrate; applying a firstcarbon nanotube composite layer on a surface of the first substrate toobtain a first electrode plate; applying a second carbon nanotubecomposite layer on a surface of the second substrate to obtain a secondelectrode plate; and assembling the first and second electrode plates;wherein the first and second electrode plates are prepared by acontinuous operation device, the continuous operation device comprises afirst shaft roller, a second shaft roller, a third shaft roller, acontainer, a platform, a tubular furnace, a traction device, an airflowapparatus, a removal device, and a laser; the first shaft roller, thesecond shaft roller, and the third shaft roller are located separatelyand axes of the first shaft roller, the second shaft roller, and thethird shaft roller are arranged along a same direction, the third shaftroller and the traction device are located on two ends of the tubularfurnace, the airflow apparatus is located between the third shaft rollerand the tubular furnace, the container has an opening and is locatedbelow the second shaft roller, and part of the second shaft roller islocated in the container, the removal device is adjacent to the secondshaft roller and a certain distance is formed between one end of theremoval device and the second shaft roller, the first shaft rollercomprises a flexible substrate, the flexible substrate is wound on thefirst shaft roller, the container is filled with a polymer solution. 2.The method of claim 1, wherein steps of fabricating the first and secondelectrode plates utilizing the continuous operation device comprises thestep of: passing the flexible substrate around the second shaft roller,the third shaft roller and the tubular furnace in sequence to connectthe flexible substrate with the traction device and forming the layer ofpolymer solution on a surface of the flexible substrate; securing acarbon nanotube array on the platform, drawing a drawn carbon nanotubefilm from the carbon nanotube array and adhering one surface of thedrawn carbon nanotube film to the layer of polymer solution on thesurface of the flexible substrate; drawing the flexible substrate withthe layer of polymer solution and the drawn carbon nanotube film thereonby the traction device at a certain speed along a direction parallel tothe axis of the tubular furnace to pass through the tubular furnace,thereby forming the carbon nanotube composite layer; and cutting theflexible substrate with the carbon nanotube composite layer thereon toobtain the first and second electrode plates.
 3. The method of claim 1,further comprising a step of disposing an insulating layer on aperiphery of the first electrode plate after obtaining the firstelectrode plate.
 4. The method of claim 1, further comprising a step ofaffixing a plurality of dot spacers on the first or second electrodeplate, the dot spacers are located between the first and secondelectrode plates.
 5. The method of claim 1, further comprising a step ofdisposing at least one first electrode on the first electrode plate, andthe at least one first electrode is located between the first and secondelectrode plates.
 6. The method of claim 5, further comprising a step ofdisposing at least one second electrode on the second electrode plate,and the at least one second electrode is located between the first andsecond electrode plates.
 7. The method of claim 1, wherein a method forapplying the first carbon nanotube composite layer on the surface of thefirst substrate comprises the steps of: coating a layer of polymersolution on the surface of the first substrate; providing at least onecarbon nanotube film treated by a laser to improve light transmittanceof the at least one carbon nanotube film; placing at least one layer ofthe treated carbon nanotube film on the layer of polymer solution; andinfiltrating the layer of polymer solution into the at least one layerof the treated carbon nanotube film and solidifying the layer of polymersolution.
 8. The method of claim 7, wherein a power density of the laseris greater than 0.1×10⁴ Watt per square meter.
 9. The method of claim 7,wherein the step of placing at least one layer of the treated carbonnanotube film on the layer of polymer solution comprises the sub-stepsof: disposing two or more stacked layers of the treated carbon nanotubefilm on the layer of polymer solution.
 10. The method of claim 9,wherein each of the two or more layers of the carbon nanotube filmscomprises a plurality of carbon nanotubes arranged substantially along asame direction; and an angle between the longitudinal axes of the carbonnanotubes of the two or more layers of the carbon nanotube films rangesfrom about 0 degrees to about 90 degrees.
 11. The method of claim 7,wherein the at least one carbon nanotube film > comprises a plurality ofcarbon nanotubes arranged along different directions.
 12. The method ofclaim 7, wherein the at least one carbon nanotube film is a drawn carbonnanotube film, the drawn carbon nanotube film comprises a plurality ofcarbon nanotubes substantially arranged along a same direction.
 13. Themethod of claim 12, wherein steps for fabricating the drawn carbonnanotube film comprises: providing a carbon nanotube array; selectingcarbon nanotubes from the carbon nanotube array; drawing the carbonnanotubes along a direction perpendicular to the growth direction of thecarbon nanotube array.
 14. The method of claim 7, wherein steps forinfiltrating the layer of polymer solution into the at least one layerof the treated carbon nanotube film comprises a step of pressing the atleast one carbon nanotube film towards the layer of polymer solutionwith air speeds of about 10 meters per second to about 8 meters persecond.
 15. The method of claim 7, wherein steps for solidifying thelayer of polymer solution comprises a step of heating the polymersolution to a predetermined temperature.
 16. The method of claim 15,wherein the step of heating the polymer solution comprises a step ofplacing the layer of polymer solution in a furnace to heat or irritatethe layer of polymer solution by laser.